As a cutting insert used when a workpiece, such as metal, is subjected to a milling process, an indexable insert described in Japanese Unexamined Patent Publication No. 2003-231015 (Patent Document 1) has been known. The indexable insert described in Patent Document 1 is made up of an indexable insert body (body member) composed of a sintered body, such as cemented carbide or ceramics, and a diamond insert (cutting edge member). A recessed part is disposed at an intersecting portion of a side flank surface and a front flank surface on a rake surface of the indexable insert body, and an insert is brazed to the recessed part.
The diamond insert is provided with an outer side cutting edge and a bottom cutting edge, namely, the outer side cutting edge and the bottom cutting edge are made of diamond, thereby enhancing the strength of a cutting edge. A through hole extends from a rake surface located at the front in a rotation direction to a surface located at the rear in the rotation direction in the indexable insert. The indexable insert is configured to be attached to a rotary cutting tool body (holder) by inserting a clamp screw member into the through hole.
In the configuration that the cutting edge member is connected to the recessed part in the body member as is the case with the cutting insert described in Patent Document 1, a region with a small thickness is formed between the recessed part and the through hole. Durability can become insufficient in the region with the small thickness, for example, when the cutting insert is miniaturized.
The present embodiments are intended to provide a cutting insert having good durability when the cutting insert is made up of a body member and a cutting edge member.